Abstract: A rotor for a rotary wing aircraft has two damping structures on the outs of the blade angle adjustment sleeve. Each damping structure is a sandwich of an elastomeric layer between two stiff cover layers. A two-armed strut passes through the blade neck and is connected at its center in a pivoting manner to the blade root. The threaded outer ends of the two-armed struts pass through the respective sandwich for yieldingly connecting the radially inner end of the blade angle adjustment sleeve to the blade root. By tightening nuts on the threaded strut arms the elastomeric layer may be compressed. Thus, the damping structure performs, in addition to the damping function, a connecting function for the blade angle adjustment sleeve.

Abstract: An airfoil particularly suited for use in rotor blades of large wind-driven ower plants is formed in three modular sections including a nose or leading section, a spar section and a trailing section, each separately formed and subsequently assembled. In the method of the invention the spar section is formed in two separate mold units which are configured to form part of the upper and lower aerodynamic profile of the airfoil and the two spar section units are trimmed along a junction plane and then joined together at the junction plane to form the spar section of the airfoil.

Abstract: A rotor blade, for example for a rotary wing aircraft, has a wing section d a root section interconnected by a neck section surrounded by a blade angle adjustment sleeve which is stiff against torque moments for transmitting blade angle adjustment movements through the sleeve to the wing section. The trailing edge of the sleeve is provided with a gap which extends, at least partially, alongside the rear edge of the neck section for visually inspecting the neck section inside the sleeve even when the root section is connected to a rotor hub. A reflecting mirror may be used for inspecting all sides of the neck section through the gap.

Abstract: A flexible blade neck of a helicopter rotor blade is bridged by a torsion gid sleeve for the blade angle adjustments. The radially outer end of the blade neck and sleeve are rigidly connected to the wing section of the blade. The radially inner end of the blade neck forms a blade root which is secure to the rotor head or hub. Additionally, the radially inner ends of the blade root and of the sleeve are interconnected by a ball and socket arrangement permitting a universal movement between the sleeve and the blade neck, thereby decoupling sleeve movements from the blade neck and vice versa.

Abstract: A cementitious composite material exhibiting an exceptional combination of high tensile, flexural and compressive strengths as compared with generally accepted values for Class H cements is produced from a mixture having a low pH and containing a tobermorite-like gel.

Abstract: A large surface structural component, such as a rotor blade for a windmill r a blade root for a windmill rotor, includes a hollow core (6) of foam material supporting a shell (8, 11) of fiber reinforced synthetic material. Positive templates in the form of disks (5) are inserted into the core (6). These templates are preferably spaced from each other along the length of the structural component and have a shape which defines the cross-sectional contour of the finished component. Thus, initially foam sections having a shape convenient for their production and these templates are assembled on a rotatable arbor (2) which is then rotated in a machining operation such as cutting and/or grinding on a lathe type machine. The shape of these templates (5) provides a guide for the machining operation which is thus substantially facilitated while simultaneously permitting the use of foam cores having initially plane surfaces.

Abstract: A window-guiding and sealing assembly for use particularly in a door of a passenger-type automotive vehicle having a window frame comprises a guide member directly attached to the window along a substantially vertical edge thereof and projecting into the interior of the vehicle, this guide member being slidably mounted in a vertical guide rail on the vehicle body. A hollow substantially oval sealing strip is integrally formed with a holder having a resilient clip for forming a snap-lock engagement with a flange and a recess along the members of the window frame, the holder having a guide surface on a horizontal portion for facilitating the engagement of an upper part of the window pane and a horizontal section of the sealing strip upon a closing of the window assembly. The holder is further provided along its entire length with an inwardly facing shoulder for engaging another hollow sealing strip attached to the door frame.

Abstract: The present rotor blade is constructed as a so-called monocoque or shell type blade for use in large fans and windmill rotors. For this purpose the blade is made of fiber reinforced synthetic material with a differnt orientation of the fibers in different sections of the blade. The transition between the blade proper and the connecting end of the blade is formed by a blade root section which has a connecting end of circular or elliptical cross-section and a wing facing end corresponding in cross-section to the blade cross-section. The blade root section has three zones. In the main leading edge zone including the leading edge and adjacent sides of the blade root section the reinforcing fibers extend in parallel to one another. The fibers also extend unidirectionally in a rear zone forming the trailing edge of the blade root section and in this trailing edge zone the fibers also extend in parallel to one another but at an angle relative to the fibers in the leading edge zone.

Abstract: A mold half is provided particularly for laminated parts which are to be ded from fiber components, with the mold half being formed with an inside surface matching the negative contour of the part to be molded therein. The mold half is formed of a shaped plate material which has been plastically deformed along deformation lines at angles determined by the shape of the part to be molded. The mold half is affixed upon a support member which fits the shape of the deformed material.